"If any one attempts to leave the house," was the command, "fire! If any one attempts to enter, allow them to do so and then give the customary call." "Bueno!" was the response, and all but the one withdrew. A minute later Adrian again arose to a crouching posture and as the sentry cautiously approached the door, he crept up behind him. An instant more and he was upon the man and had him by the throat. The man was a wiry Mexican and evidently in training, for he squirmed and kicked vigorously; but Adrian's grip was too firm upon him and in a couple of minutes he sank down limp upon the ground. The noise of the scuffle must have been heard inside, for the door cautiously opened and a head peered out. Without a question Adrian sprang within, dragging the lifeless form of the sentry with him. "Quick, bar the gate!" he commanded. The command was obeyed. "Now where is Mr. Black?" he asked. "Upstairs talking with Jose." "All right. Bind this man while I go up. Don't let him escape or he is liable to cut your throat." "_No temer V, senor_" was the response, meaning "Have no fear." Adrian ran lightly up the stairs, revolver in hand. He heard voices talking and had no doubt that Jose was narrating some trumped-up story. "Yes, senor," he heard the mozo say, "they are expecting you. It is necessary that you go at once." Adrian flung open the door and covered Jose with his revolver. "Put up your hands," he commanded. Then to Mr. Black, to whom Jose was talking: "Take his weapons away from him, Mr. Black." Realizing at once that something was wrong, Mr. Black obeyed. "Now tie him." This was also quickly done, Mr. Black asking at the same time what had happened. "I can't tell you exactly, Mr. Black, but this man has betrayed us and we are now watched by a squad of soldiers." Mr. Black's face turned as black as his name. "Is that true?" he demanded, seizing Jose by the shoulder with such a powerful grip that the man cried out with pain. "Oh, senor," he cried, "don't kill me! I will tell you all." "See that you do," was the command. "One lie and I will wring your neck as I would a chicken. You know me." "I'll tell the truth. I told the captain at the barracks. He is going to capture all the Americanos and hold them for ransom and I am to have half." "That is evidently the truth," declared Adrian, and he proceeded to tell Mr. Black what was being done to get him and his daughter to Vera Cruz, and how Jose had played them false. For a moment it looked as though Mr. Black might wreak his vengeance on Jose, but after a minute he thought better of it. "You ought to die this minute," he declared, "but I'll wait till I have more time." Then to Adrian: "What had we better do now?" Before Adrian could reply the clear note of a bugle rang out upon the night air. CHAPTER XXI. ADRIAN HAS AN ACCIDENT. "What do you suppose that means?" asked Adrian. Mr. Black made no reply and a moment later the bugle call was repeated.